Disk drives are information storage devices that use magnetic media to store data. Referring to FIG. 1, a typical disk drive in related art comprises a head stack assembly (HSA) 904 with slider(s) 903 thereon, a magnetic disk 901 mounted on a spindle motor 902 to spin the magnetic disk 901, and a housing 907 to enclose the above-mentioned components. The slider(s) 903 is including in sensor to read data from or write data to the surface of the magnetic disk 901 by surfacing over it, which is positioned radially by a voice coil 906 embedded (e.g. by epoxy potting or overmolding) in a fantail spacer 908 of the HSA 904. Generally, a voice coil motor (VCM) 914 is used to drive the voice coil 906.
Referring to FIGS. 2(a) and 2(b), the HSA 904 comprises four head gimbal assemblies 971, 973, 975 and 977. In the related art, the HSA 904 further comprises a spacer 81′ interposed between the head gimbal assembly (HGA) 971 and the HGA 973, a fantail spacer 831′ sandwiched between the HGA 975 and the HGA 977, and a plurality of securing means to couple the four HGAs 971, 973, 975, 977 with the spacer 81′ and the fantail spacer 831′ together. A flexible printed circuit (FPC) 9′ is aligned with the fantail spacer 831′ by a FPC assembly 835′ formed at an end of the FPC 9′ to electrically connect with the four head gimbal assemblies 971, 973, 975, 977. The FPC assembly 835′ has a plurality of solder pads 999 thereon. Referring to FIG. 2(c), the fantail spacer 831′ has a mounting block 839′ with an opening 838′ formed therein used for aligning with the FPC assembly 835′. In the related art, the plurality of securing means comprises a bearing 70′, a washer 76′ and a nut 78′. Each of the four head gimbal assemblies 971, 973, 975, 977 forms a big hole (not labeled) therein and so does the spacer 81′ and the fantail spacer 831′. These big holes are provided to permit the bearing 70′ extend therethrough so as to combine these parts together with the help of the washer 76′ and the nut 78′.
In the related art, also referring to FIGS. 2(a) and 2(b), each of the four head gimbal assemblies 971, 973, 975, 977 has a suspension flexure cable (not labeled) running from the slider 903 to a trace terminal of the suspension flexure cable (the trace terminals of the HGAs 971, 973, 975, 977 are labeled as “961”, “963”, “965”, “967”, respectively). Each of the trace terminals 961, 963, 965, 967 forms a plurality of terminal pads 99 corresponding to the solder pads 999 and each of the terminal pads 99 is shaped as a through-hole. The layout of the terminal pads 99 on each of the trace terminals 961, 963, 965, 967 is same as the other.
Referring to FIG. 2(a), when the HSA 904 is assembled, the trace terminals 961, 963, 965, 967 are positioned on the FPC assembly 835′ and a slot 8 is defined between two adjacent trace terminals of the trace terminals 961, 963, 965, 967. In the related art, the HGAs 971, 973, 975, 977 are electrically connected with the FPC 9′ by solder bonding the terminal pads 99 of the trace terminals 961, 963, 965, 967 with the solder pads 999 of the FPC assembly 835′.
However, the traditional method uses solder bonding process for connecting HGA with FPC. It results in occurrence of component contamination. To avoid component contamination, it is necessary to clean the HSA after solder bonding process. Such cleaning process is also rather difficult and costly. More seriously, the solder bonding process might cause a damage of the surrounding electrical components and/or disk media. In addition, the HSA assembly line and the hard disk drive (HDD) assembly line cannot be integrated together because the HSA must be cleaned before it is mounted in the housing of the disk drive. Furthermore, there is a case to separate the HGA with the FPC for rework (repairing or replacing) when there is something wrong with the HGA or the FPC. However, separating the HGA with the FPC is also troublesome because the solders bonded therebetween must be deleted. Accordingly, reworking the HSA is rather time-consuming and costly. Finally, because the terminal pads on each of the trace terminals has the same layout, it makes the electrical traces of the FPC, which connect with the terminal pads, rather jam-packed and accordingly the design and fabrication of the IC module of the FPC becomes difficult.
It is therefore desirable to provide a HSA and manufacturing method thereof, a disk drive unit using the HSA to solve the above-mentioned problems.